As with many antennae, you will need to figure out whether you need something that:
- needs a long coax cable
- has a high-gain antenna (if the isdb signal is weak in the house/area)
- can be used both indoor and outdoor
- needs an amplifier to get a clear signal
- can attach itself to the tv
- is pet- and child-proof
I suggest you do a quick search in Lazada (or Shopee) for "digital antenna" and then just pick whatever you think works for you.
Generally speaking, any antenna with about 16db should be ok for most people.